One important factor in choosing ingredients for foods and cosmetics is the requirement to select only those that are human safe and environmentally benign. The use of GRAS and especially natural or naturally-derived materials, i.e. those referred to as “green”, is also very much of interest in topically applied and ingested compositions. Thus, such materials reduce the likelihood of adverse reactions to the human body if absorbed into the body through the skin.
Although food safe and naturally derived Nα-long chain alkanoyl di basic amino acid alkyl ester salts have been known since the 1960's, one of the first patents to recommend these amino acids, specifically for food applications was U.S. Pat. No. 3,825,560 (issued Jul. 23, 1979). A number of derivatives are disclosed including Nα-cocoyl-L-arginine ethyl ester pyrrolidone carboxylate and Nα-lauroyl-L-arginine methyl ester hydrochloride. Since this publication, there have been several more patents issued or published disclosing specifically Nα-lauroyl-L-arginine ethyl ester hydrochloride salt (LAE-HCl). These include U.S. Pat. No. 5,780,658 that discloses a process to prepare LAE-HCl, as well as disclosing its use for food applications. U.S. Pat. No. 7,074,447 B2 discloses an antimicrobial composition comprising LAE-HCl with potassium sorbate. U.S. Pat. No.7,087,769 is another process patent suggesting its use for food. Two patent publications, U.S. 2004/0166082 and U.S. 2004/0175350, disclose dibasic amino acid alkyl ester salts useful for cosmetic applications. U.S. 2004/0254232 covers the oral care use while U.S. 2004/0265443 covers food. U.S. 2005/0175747 discloses complexes formed between LAE-HCl and various anionic hydrocolloids.
In addition to bacteria, fungi, yeasts and molds, many cationic surfactants are known for their anti-viral activity. Indeed, US patent publication U.S. 2009/0326031 discloses the use of Nα-lauroyl-L-arginine ethyl ester hydrochloride for the prevention and treatment of viral infections including influenza and herpes viruses.
The literature provides numerous references concerning glycerol monofatty acid esters having antiviral and antibacterial activity. The most active monoglycerides consist of those esters formed from saturated fatty acids having from 6 to 14 carbon atoms. U.S. Pat. No. 4,997,851 teaches the use of saturated fatty acids and glycerol monofatty acid esters as effective antiviral agents against the HIV and HSV-1 viruses. They were also active against a variety of gram positive and gram-negative bacteria.
U.S. Pat. No. 5,434,182 discloses the spermicidal, antimicrobial and cytocidal activity of glycerol monofatty acid esters. It discloses the combination of fatty acyl glycerides, a chelating acid, and a surfactant which confer excellent antimicrobial activity for preserving processed meats and for disinfecting poultry carcasses. When only one of these three agents was used, the anti-microbial performance was considerably reduced. U.S. Pat. No. 6,414,023 B1 discloses the use of fatty acid monoglycerides in conjunction with 2,4-dichlorobenzyl alcohol.
U.S. Pat. No. 6,638,978 B1 lists a preservative formulation for food and cosmetics consisting of glyceryl mono-laurate (monolaurin, ML), a mixture of caprylic and capric acid and propylene glycol in an aqueous base. U.S. 2005/0084471 A1teaches the preparation of a preservative for meat, fruits, and vegetables and for the disinfection of inanimate surfaces. The actives include a propylene glycol C7-C14 fatty acid ester as the major component, a surfactant, and an enhancer. Enhancers include phenolic antioxidants and/or a paraben ester. Lastly, U.S. Patent 2006/0030512 A1 describes a long lasting anti-microbial film comprising a glycerol monoester, an amphoteric surfactant, a chelating agent and a solvent like propyl alcohol plus other incipients.